class_docstr: Add a random flipping layer as pre-processing.
code: def randomise(self, spatial_rank=3):
      spatial_rank = int(np.floor(spatial_rank))
      self._rand_flip = (
          np.random.random(size=spatial_rank) < self._flip_probability
      )
  
file_path: NiftyNet/niftynet/layer/rand_flip.py
imports: from __future__ import absolute_import, print_function
  import warnings
  import numpy
  from niftynet.layer.base_layer import RandomisedLayer
label_desc: Use image node_id 2 for calling the RandomFlipLayer obj's underlying member method code with example usage: obj.randomise(spatial_rank) without return types